The Nutritional Epidemiology Section is the focus of nutritional expertise within the Epidemiology and Biostatistics Program. Members of the Section explore nutritional hypotheses in cancer etiology in a variety of studies either with a core of nutritional issues or as collaborators on large projects with nutritional components. In addition. members often consult on other projects within the Program. The major efforts investigate the etiologic role of nutrients or foods in analytic studies targeted to breast, reproductive, lung, colorectal and other cancers. Biochemical and anthropometric investigations augment the dietary analyses and provide the opportunity to evaluate biologic intermediates and mechanisms for risk factors. Descriptive dietary analyses provide basic information for further studies and important data on correlates of nutrients and other risk factors. Dietary methodologic research has been a recent focus. both on developing better means of assessing nutrients and non-nutrient food constituents. vitamin supplements and hidden sources of fat. as well as better laboratory techniques for assessing micronutrients and hormones. New hypotheses related to heterocyclic amine exposure from cooked meats have been pursued in human metabolic studies. analytic studies. evaluation of variation due to genetic susceptibility and development of dietary assessment methods including questionnaire and database development.